Facts about the Aurora (Northern/Southern Lights)
- 08
Southern hemispheric auroras occur simultaneously with northern lights due to Earth's magnetic field geometry, creating mirror phenomena called aurora australis in Antarctica and southern latitudes.
- 07
Astrophysicist Kristian Birkeland demonstrated in 1896 that cathode rays mimicking solar wind could create glowing rings around magnetized spheres, proving the aurora resulted from charged particle interactions rather than atmospheric chemistry alone.
- 06
Auroras typically occur in oval-shaped zones centered 3-6 degrees from Earth's magnetic poles, known as the auroral oval, rather than directly at the poles themselves.
- 05
Solar wind particles collide with Earth's magnetosphere at speeds exceeding 45 kilometers per second, creating the charged particle cascades that generate auroral light in the upper atmosphere.
- 04
In 1859, the Carrington Event produced auroras so bright that people could read newspapers at midnight in Boston, the most intense geomagnetic storm ever recorded.
- 03
Nitrogen atoms produce the rare deep red auroras that occur above 300 kilometers altitude, visible only during the most intense geomagnetic disturbances.
- 02
Geomagnetic storms rated 5 on the KP index can trigger auroras visible as far south as the northern United States and southern Canada during intense solar wind events.
- 01
Oxygen atoms in the thermosphere produce the green auroras visible at 100-300 kilometers altitude, the most common color of northern lights displays.